1. Field of the Invention
The present invention pertains to a cemented carbide which is excellent in toughness and wear resistance and is suitably used for solid end mills, solid drill bits and wire members.
2. Prior Art
Heretofore, print pins of a dot printer, solid end mills or solid drill bits have been often made of WC-based cemented carbide since high wear resistance is required. Such conventional cemented carbide includes a hard dispersed phase composed of tungsten carbide and a binder phase composed of 4 to 20% by weight of one or two metals of cobalt and nickel. In some cases, the hard dispersed phase further contains 0.1 to 40% by weight of one or more of compounds selected from the group consisting of carbides of metals in Groups IV.sub.A, V.sub.A and VI.sub.A of the Periodic Table other than tungsten, nitrides of metals in Groups IV.sub.A and V.sub.A of the Periodic Table and solid solution of two or more of these carbides and nitrides.
Although the prior art cemented carbide as mentioned above has been superior in wear resistance, it has been inferior in toughness, thereby being susceptible to breakage in actual use. This has been especially the case with apparatuses developed in recent years wherein requirements for such cemented carbide are getting severe in order to achieve a higher speed operation as well as a higher performance.